[postgis-devel] [PostGIS] #384: documentation and clearifying of ~= change

[PostGIS]

#384: documentation and clearifying of ~= change
----------------------+-----------------------------------------------------
  Reporter:  nicklas  |       Owner:  robe         
      Type:  defect   |      Status:  new          
  Priority:  medium   |   Milestone:  PostGIS 1.5.1
 Component:  postgis  |     Version:               
Resolution:           |    Keywords:               
----------------------+-----------------------------------------------------
Comment (by robe):

 The difference is that = doesn't use an index and ~= uses an index.
 Except for the rare case if you put a btree index on a geometry which you
 can only do for small thngs like points.

 Am I safe in saying that we can never make = use a gist index as I assume
 since a gist is marked as lossy, it would never be able to be used in
 group by, order by etc.  Perhaps Paul, Mark or Kevin can confirm my
 understanding of this.

 Ideally we would just use = and scrap ~=, but we can't because we need a
 fast bounding box check.  Huh Paul  yap I am and I think Kevin too are
 those unbelievable people you talk about.  ~= is important (well an
 indexable bounding box equality operator)

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/384#comment:3>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.